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Roy Race View Drop Down
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Joined: 15 Aug 07
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Posts: 275 		Post Options Post Options   Quote Roy Race Quote  Post ReplyReply Direct Link To This Post Topic: Masts
    Posted: 16 May 09 at 11:08am
Originally posted by JimC

Originally posted by Guest#260

I thought it was a
great innovation and it was a shame the ratings knobbled
it


It wasn't much of an innovation - more an attempt
at a rule cheat. The idea was to have a mast that rated
as a very long section fixed mast (ie lots of drag) but
twisted so that it behaved much more like a rotating
mast drag wise. They hoped to get a rating allowance for
much more rig drag than was actually present.

The measurer, quite correctly according to the rules,
elected to give it a rating partway between a fixed mast
and a fully rotating mast, and as a result the owner
threw his toys out of the pram and went off in a huff
because he'd spent a fortune on this stick and was no
better off rating wise than if he's kept a standard one.

That particular rating rule aspired to do exactly that -
rate any innovation on the exact effect it had on boat
speed. That's the big difference between a measurement
handicap rule and a box rule.


I spent hours looking over this mast when it was laid up
on trestles in Moody's marina, one afternoon in 1999. I
thought at the time that it was one of the most
incredible pieces of engineering I'd ever seen in
sailing. If it wasn't much of an innovation, I'd love to
see something that was.
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JimC View Drop Down
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Posts: 6649 		Post Options Post Options   Quote JimC Quote  Post ReplyReply Direct Link To This Post Posted: 16 May 09 at 4:13pm
Originally posted by Roy Race

If it wasn't much of an innovation, I'd love to see something that was.

It was just another device intended to make the boat go slower, but not be as speed destroying as the rating rule calculated it to be. The reason there has never been anything else like it is that it had no virtues other than the attempt to manipulate the rating rule. Personally I despise such games.
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RS400atC View Drop Down
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Posts: 3011 		Post Options Post Options   Quote RS400atC Quote  Post ReplyReply Direct Link To This Post Posted: 16 May 09 at 5:25pm
Originally posted by Peaky

Originally posted by RS400atC

whatever happened to wing masts?

I have one

http://sailns14.org/tech.aspx

 

 

Looks like a nice boat, although I personally prefer 3 sails. What's it like sailing with a very rigid mast? My simplified understanding is that masts that bend fore and aft are fairly central to achieving gust response, such that the mast responds much faster than the crew is able too, smoothing out the fast variations in the wind.

Does rhe NS14 rig achieve this in another way? Or is the top of the mast made very flexy? Or does it not work to this theory?

BTW are your photos Chew Valley?
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Flick-Flock View Drop Down
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Joined: 27 Mar 09
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Posts: 102 		Post Options Post Options   Quote Flick-Flock Quote  Post ReplyReply Direct Link To This Post Posted: 17 May 09 at 12:23pm
Originally posted by RS400atC

Looks like a nice boat, although I personally prefer 3 sails.


Then this might take your fancy

(Stolen from the favorite photos thread)

Although i think the MG's dont have the rotating wingmast because of the kite, i may be wrong though

Frank Bethwaite talks about the rig control of an NS14 in High performance sailing, i can't remember what he says off the top of my head (like much of that book ), but i think the masts are built to flex one way but not the other.
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Guests View Drop Down
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 17 May 09 at 12:56pm

The MGs have rotating wing masts too.

My mast is untapered and therefore stiff fore/aft, but very flexible sideways.  Coupled with a square head main (as opposed to just a fat head) it still twists off perfectly well in gusts.  However, many NS's use a tapered top section to increase fore/aft flexibilty.  Neither approach is demonstrably faster judging by the results.  The latest approach is to use a constant section carbon mast but with the layup changed above the hounds to increase the flexibilty.  Sort of the best of both.

Well spotted, it is Chew.
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JimC View Drop Down
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Posts: 6649 		Post Options Post Options   Quote JimC Quote  Post ReplyReply Direct Link To This Post Posted: 17 May 09 at 5:35pm
Mast rotation with a wing mast which is stiffer fore and aft than sideways has all sorts of interesting effects on the rig and sail twist... Difficult to describe, you can only really watch it happening, put simply, over rotation causes the mast tip to climb up to windward which gives amazing twist control. Its used to quite astonishing extremes with DN ice boats...

Something that would be very interesting to explore with wing masts would be some kind of torsion control that gave the top of the mast twist compared to the bottom to match the twist in the sail... *very* hard to do right I imagine.

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Guest View Drop Down
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Posts: 0 		Post Options Post Options   Quote Guest Quote  Post ReplyReply Direct Link To This Post Posted: 17 May 09 at 6:36pm

Originally posted by JimC

Originally posted by Roy Race

If it wasn't much of an innovation, I'd love to see something that was.

It was just another device intended to make the boat go slower, but not be as speed destroying as the rating rule calculated it to be. The reason there has never been anything else like it is that it had no virtues other than the attempt to manipulate the rating rule. Personally I despise such games.

I dunno why your getting your knickers in a twist JimC ... keelboat racing off ratings has always been a game of trying to get the best rating relative to your performance, that is the name of the game, every owner is doing it and this boat had a very novel approach to achieving the best performance rating ratio ... that is one of the key factors in the results. If you don't like it then sail one-design ...



Edited by Guest#260
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getafix View Drop Down
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Posts: 2143 		Post Options Post Options   Quote getafix Quote  Post ReplyReply Direct Link To This Post Posted: 19 Dec 18 at 12:08pm
So bored at work and dragging through my brain to see what I can occupy myself and y'all with over the festive period and I came upon this old thread.  

Now, since this is very old and composite masts have moved on quite some way, I wonder if an unstayed (at deck level) mast with <single> trapeze is now an option?
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Sam.Spoons View Drop Down
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Posts: 3398 		Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 19 Dec 18 at 1:13pm
Windsurfers do it all the time  Wink
Spice 346 "Flat Broke"
Blaze 671 "supersonic soap dish"
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getafix View Drop Down
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Posts: 2143 		Post Options Post Options   Quote getafix Quote  Post ReplyReply Direct Link To This Post Posted: 19 Dec 18 at 4:18pm
indeed... I like the ability to take down the mast and transport the boat easily and quickly, I doubt a two part is practical with a trapeze, but even a single section un-stayed is quicker to rig than one with shrouds and forestay and does allow for the possibility to have more movement from the spar factored into the sail design and behavior?

I'm also wondering if un-stayed rigs enable cheaper hull construction, in the same way daggers versus centerboards, as although the loads are roughly equivalent, you don't need to resist the forces from shrouds/lowers in the side decks as well as at mast foot & gate level and you don't have to factor a forestay loading into your bow design?
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